首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   420篇
  免费   42篇
耳鼻咽喉   3篇
儿科学   4篇
妇产科学   12篇
基础医学   85篇
口腔科学   13篇
临床医学   44篇
内科学   94篇
皮肤病学   13篇
神经病学   22篇
特种医学   7篇
外科学   82篇
综合类   4篇
预防医学   21篇
眼科学   11篇
药学   20篇
中国医学   1篇
肿瘤学   26篇
  2024年   1篇
  2023年   9篇
  2022年   22篇
  2021年   26篇
  2020年   11篇
  2019年   15篇
  2018年   16篇
  2017年   14篇
  2016年   14篇
  2015年   9篇
  2014年   12篇
  2013年   14篇
  2012年   18篇
  2011年   35篇
  2010年   14篇
  2009年   12篇
  2008年   24篇
  2007年   32篇
  2006年   18篇
  2005年   28篇
  2004年   16篇
  2003年   19篇
  2002年   5篇
  2001年   6篇
  2000年   10篇
  1999年   5篇
  1998年   4篇
  1997年   5篇
  1996年   3篇
  1995年   2篇
  1994年   1篇
  1993年   4篇
  1992年   6篇
  1991年   3篇
  1990年   5篇
  1989年   3篇
  1988年   1篇
  1987年   3篇
  1986年   1篇
  1985年   1篇
  1984年   4篇
  1983年   1篇
  1982年   1篇
  1979年   4篇
  1976年   1篇
  1969年   2篇
  1967年   1篇
  1965年   1篇
排序方式: 共有462条查询结果,搜索用时 0 毫秒
1.
S Mihok  L H Otieno  N Darji  D Munyinyi 《Acta tropica》1992,51(3-4):217-228
Teneral Glossina morsitans centralis, G. m. morsitans and G. pallidipes were infected with three different clones of Trypanosoma brucei in blood containing D(+)-glucosamine, an inhibitor of tsetse midgut lectin. On average, 5 days of D(+)-glucosamine treatment tripled infection rates, without affecting the proportion of infections that matured. Total infection rates were equal in males and females, but twice as many infections matured in males. Counts of parasites in the guts and salivary glands of 277 flies revealed order of magnitude differences among flies, with females consistently having 2-3-times as many parasites as males. Parasite numbers varied in a sex-specific manner among tsetse-clone combinations, but these differences were not correlated with similar large differences in infection rates. D(+)-glucosamine treatment had no significant effect on parasite loads.  相似文献   
2.
3.
BACKGROUND. Four hundred thirty-three patients with recurrent breast cancer were treated by the authors at a large medical breast oncology facility from 1976-1982. The median survival time from first relapse (MSFR) for the 193 patients whose survival experience was not confounded by lead-time bias was 26 months. This MSFR is similar to that of most series published in the 1970s and 1980s and is approximately double that of series published in the 1960s. METHODS. In this series, regression analysis identified disease-free interval (DFI), estrogen receptor (ER) status, and dominant disease site as significant prognostic variables, similar to other published series. RESULTS. In 113 patients with known ER values, DFI, and dominant metastatic sites, a prognostic spectrum of MSFR patterns was identified among combinations of these three variables. The MSFR ranged from 15 months for poor risk patients with negative ER values, visceral dominant sites, and DFI of less than 24 months, to more than 90 months for good risk patients with positive ER values, soft tissue dominant sites, and DFI of more than 24 months. Although menopausal status alone was not a significant prognostic variable in regression analysis, 66% of premenopausal patients had a constellation of "poor" prognostic variables. CONCLUSIONS. This type of prognostic factor analysis at first relapse could help identify subsets of patients who might be considered for aggressive investigational therapies such as high-dose chemotherapy with autologous bone marrow reconstitution.  相似文献   
4.
ObjectiveTo describe an arthroscopic technique for giant meniscal cyst excision with preservation of the functional meniscus, report the short‐ and medium‐term outcomes, and assess magnetic resonance imaging (MRI) for follow‐up imaging evaluations.MethodsA total of 54 consecutive patients with symptomatic meniscal cysts were admitted to the Second Xiangya Hospital of Central South University between 2014 and 2019. Nine patients with giant meniscus cysts (six females and three males) were included in this study. The age range of the patients was 6–34 years. All patients underwent a complete physical examination, X‐ray, Doppler ultrasound, and MRI of the knee preoperatively. After an arthroscopic diagnosis of a meniscal rupture with a giant meniscal cyst, partial meniscectomy, ablation of the cyst, and suturing of the retainable meniscus were performed. Lysholm and International Knee Documentation Committee (IKDC) scores were used preoperatively and at the most recent follow‐up. Clinical outcomes were classified into four categories: excellent, good, fair, and poor. During the last visit, all patients underwent MRI to assess the recurrence of the cyst and meniscal suture healing.ResultsPreoperative MRI and arthroscopic examination revealed giant meniscal cysts combined with meniscal tears and congenital discoid meniscus, and all giant meniscal cysts occurred in the lateral meniscus. The main types of meniscal tears were horizontal and complex tears. The cysts were unicystic in one case and multicystic in eight cases. The mean size of the cysts on the MRI was 5.86 cm × 2.24 cm × 2.48 cm. The mean follow‐up periods were 37.5 (19–60) months. Clinical outcomes were excellent in six patients and good in three patients. The postoperative scores were significantly improved compared to the preoperative scores (Lysholm: 90.78 ± 4.60 vs. 54.56 ± 7.25; IKDC: 96.2 ± 3.46 vs. 61.69 ± 3.36; p <0.01). No recurrence of the cyst was indicated on the MRI, and there was good healing of the torn meniscus.ConclusionsArthroscopic cystectomy combined with the meniscus suture technique was effective to eradicate residual cyst cavities, and traffic orifices be highly recommended.  相似文献   
5.
Swine influenza viruses (SIV) produce a highly contagious and worldwide distributed disease that can cause important economic losses to the pig industry. Currently, this virus is endemic in farms and, although used limitedly, trivalent vaccine application is the most extended strategy to control SIV. The presence of pre-existing immunity against SIV may modulate the evolutionary dynamic of this virus. To better understand these dynamics, the viral variants generated in vaccinated and nonvaccinated H3N2 challenged pigs after recovery from a natural A(H1N1) pdm09 infection were determined and analyzed. In total, seventeen whole SIV genomes were determined, 6 from vaccinated, and 10 from nonvaccinated animals and their inoculum, by NGS. Herein, 214 de novo substitutions were found along all SIV segments, 44 of them being nonsynonymous ones with an allele frequency greater than 5%. Nonsynonymous substitutions were not found in NP; meanwhile, many of these were allocated in PB2, PB1, and NS1 proteins. Regarding HA and NA proteins, higher nucleotide diversity, proportionally more nonsynonymous substitutions with an allele frequency greater than 5%, and different domain allocations of mutants, were observed in vaccinated animals, indicating different evolutionary dynamics. This study highlights the rapid adaptability of SIV in different environments.  相似文献   
6.
7.
8.
During studies to determine the main Trypanosoma brucei rhodesiense transmission sites in Lambwe Valley, Western Kenya, Glossina pallidipes were collected from two areas in the valley and examined for trypanosome infection. T. brucei isolated from infected flies were tested for their response to the lethal effects of human blood (Blood Incubation Infectivity Test, BIIT) and also characterized using isoenzyme electrophoresis. Six of the 26 T. brucei tested were BIIT positive, two of which had enzyme profiles identical to human isolates. The 26 isolates were grouped into 10 zymodemes. Two zymodemes were identical to T. b. rhodesiense isolated from sleeping sickness patients, one of which was identical to the predominant zymodemes among patients from Lambwe Valley area. The other zymodeme was identical to an isolate from a patient from the Busoga (Uganda) sleeping sickness epidemic focus. These two Zymodemes were BIIT positive. It is suggested that there has been an exchange of human infecting organisms between the Kenya and the Uganda foci.  相似文献   
9.
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号